Internal combustion motor



` May 18, 1937.

T. c. MARSHALL INTERNAL COMBUSTION MOTOR Filed July 2, 1935 5 Sheets-Sheet l May 18, 1937. T. c.. MARSHALL INTERNAL COMBUSTION MOTOR Filed July?, 1955 3 sheets-sheet 2 z a 7 2 2 .51 2 a 2 W .w /////rf 1 6 a 2 2 1 100 a 4 n m 1 May 18, 1937. T. c. MARSHALL INTERNAL COMBUSTION MOTOR Filed July 2, 1935 3 Sheets-Sheet 5 lll Patented May 18, 1937 Uli-E ""E'TES PATENT FIQE INTERNAL COMBUSTION MOTOR l Thomas Clarence Marshall,- Yorklyn, Del. l .v Application July. 2, 1935, Serial No. 29,531 f 17 Claims.

This invention relates to certain improvements in internal combustionmotors, and more particularly to the automatic control ofthe motor intake vacuum conditions and of the fuel mixture; and the nature and objects of the invention will be readily recognized and understood by those skilled in the arts involved in the light of the following explanation and detailed description of the accompanying drawings illustrating what I at present considerto be the preferred embodiments or mechanical expressions of my invention from among various other forms, designs, arrangements, combinations and constructions of which the invention is capable Within the broad spirit and scope thereof.

An internal combustion motor in an .automotive vehicle, for example, is subjected under the varying conditions encountered in the operation of such a vehicle, to the effects of varying degrees of vacuum established in the motor intake b-y suction created by the operation of the motor pistons. Thissuction is utilized to draw the combustible mixture from a carburetor or other suitable source into the combustion chambers of the cylinders through the motor intake line, and when the suction demands of the motor exceed the capacity of the motor' intake line as determined by the motor throttle setting, then a vacuum condition isestablished in the intake lineI and motor. As the `motor must operate against or in opposition- -to this intake vacuum condition there is as a result a reduction in the power and eiciency of the motor, as Well as the imposition of considerable strains on the Working parts of the motor, such as the piston, connecting rods, and bearings. Such intake vacuum conditions also tend to cause lubricating oil to be forced or drawn past the pistons into the combustion chambers of the cylinders, where the oil is' burned and leaves deposits of carbon in the combustion chambers and associated parts of the motor.

During the operation of an automotive vehicle there are periods of time during which the motor is functioning substantially as a suction pump with the throttle valve of the motor in motor idling or low speed position, that is substantially closed for low fuel supply to the motor, with the result that a very harmful condition of high vacuum is established in the motor and intake line, .and fuel is being drawn into the motor of a richness and quantity greatly above the actual fuel requirements of the motor under such conditions. These periods of high vacuum are encountered particularly when a motor Vehicle is coasting down grade with the motor throttle valve in idlingpositi-on, or as the result of deceleration by closing the. throttle valve, so that the motor is not only working against such condition of vacuum but is being charged with fuel mixture which is in partwasted and fouls the motor upon accelerationof the motor following such a period of high vacuum. v

With a motor idling and the motor vehicle at rest there is normally a condition of relatively high'vacuum, but upon acceleration of the motor by opening theY throttle, and with the vehicle driven by the motor, it is found that the vacuum condition decreases with the opening of the throttle untilthe vehiclerhas attained a desired speed and the opening of the throttle for the acceleration` to such speed is stopped, whereupon the vacuum condition Aagain increases and is maintained until further acceleration, When the vacuum again tends to decrease.

At the maintained speed after acceleration, it 2o is found that the fuel mixture normally supplied to the motor can be substantially cut down as to fuel content, that is leaned, with amaterial saving in fujelas well as an increase in motor eiciency, and furthe-r, that if the vacuum condition can also be reduced simultaneouslyy with the reduction inrichness`- of the fuel mixture, then the performance and'efciency of themotor are still further increased. However, as the fuel mixture and the motor throttle valve settings must be adapted forfthefbest average results through the full operating and speed range of the motor, the more elicient fuel mixture and vacuum conditions for the higher speed ranges are not suitable to operation ot the motor in the lower speed and motor idling ranges', and must be changed to different conditions in the latter ranges, if the proper fuel mixtures for motor performance and control are to be obtained. Thus, efficiency and power of a motor throughout the full operating and speed ranges are sacric'ed in the present design of motors and operating practice, by the necessity for compromise and the resulting operation of a motor at the best average conditions adapted for the full range of operations, without regard to the most efcient conditions at any particular operating range.

It is a general object of my present invention` to` overcome the foregoing moto-r vacuum and fuel mixture conditions in order toV materially increase the performance and operating efficiency o-f an internal combustion motor, by providing for automatic reduction in the intake vacuum and dilution of the fuel mixture under'those motor operating conditions Where high vacuum and over rich mixtures materially lower motor eciency, but without interfering with the operation of the motor during operating conditions which call for undiluted mixtures for proper operation and at which normal intake vacuum for suoli operating conditions has no substantial effect on efficiency or performance of the motor.

A feature of my invention in carrying out the foregoing general object, resides in automatically reducing or breaking down the high vacuum in and simultaneously diluting the fuel mixture for an internal combustion motor, by admitting air into the motor intake line intermediate the source of fuel mixture and the motor whenever the vacuum for the particular conditions under which the motor is operating tends to exceeda predetermined degree of vacuum desired for such operating conditions, so that an increase in` performance and efficiency with a decrease in fuely consumption is obtained for the motor.

A further feature of the invention provides for the automatic variation or changing of the predetermined maximum vacuum in the motor intake at which air admission takes place to break down the vacuum and dilute the fuel mixture, in accordance with the setting of the motor throttle valve in order to increase the maximum allowable Vacuum with the motor throttle in idling and in partially opened settings for the low speed range of the motor, and to reduce the maximum allowable vacuum from the idling and low speed range throughout the higher speed ranges of motor operation.

Another feature and characteristic of my invention resides in obtaining variation in the maximum allowable intake vacuum through the medium of an air admission valve to the motor intake controlled by the intake vacuum, by varying the forces applied to such Valve to oppose its opening; and in controlling the increase or decrease in the forces opposing valve opening in accordance with the position or setting of the motor throttle valve. I

In accordance with a further characteristic of the invention the vacuum of the motor intake, under the control of the motor throttle valve and its operating mechanism, is utilized to apply the increased forces to the air admission valve of the motor intake line that oppose the opening of the valve, and to release such increased forces, all in accordance with the setting or position of the throttle valve.

As further features the invention provides for the control and variation of the closing forces applied to the air admission valve, either through electrically operated or mechanically operated means, and in either instance the control of such means by the throttle valve and its operating mechanism in accordance with the setting or position of the motor throttle valve.

It is also a further general object of the invention to provide a device or apparatus having the features and characteristics above referred to, that is, readily adapted to mounting on existing motors or which can be built-in as an original part of a motor; and toprovide a design and arrangement of such apparatus that will be of relatively low cost and of simple and uncomplicated construction, yet which will be durable in use and positive and efficient in operation.

With the foregoing general objects, features and characteristics in View, as well as certain others which will be readily apparent from the following description, my invention consists in certain novel features in design and construction,

and in arrangement, combination and operation of parts and elements, all as will be more fully and particularly referred to and specified hereinafter.

Referring to the accompanying drawings, in which similar reference characters refer to corresponding parts throughout the several figures thereof:

Fig. 1 is a View in side elevation of portions of an internal combustion motor of an automotive vehicle including the motor intake line, intake manifold, carbureter, throttle valve and its operating mechanism, with a preferred form of the `invention installed and mounted on the motor in operative connection therewith, the motor throttle valve and its operating mechanism being shown in normal setting for motor idling.

Fig. 2 is a vertical longitudinal section through the air valve unit and its operating and control means of Fig. l, the valve being shown in closed position held against opening by the combined forces exerted thereon by the upper and lower springs thereof.

Fig. 3 is a view similar to Fig. 2, but with the lower spring released by the intake vacuum operated piston, and the air valve in open position against the force of the upper spring of the valve.

Fig. 4 is a transverse horizontal section through the valve of the valve unit and the valve seat adjusting ring, taken as'on the line 4 4, of Fig. 2.

Fig. 5 is a View partly in elevation and partly in vertical section of a modification showing a solenoid form of valve force applying means, and

- showing more or less diagrammatically the solenoid circuit and controlling switch for operative connection with the motorV throttle operating mechanism.

Fig. 6 is a View in side elevation, more or less diagrammatic, showing another form of solenoid circuit controlling switch.

Fig. 7 is a vertical longitudinal section through the air valve unit with the valve in closed position, and showing a further modification embodying a mechanical form of means controlled by the throttle valve operating mechanism for applying and releasing the lower valve spring forces to and from the valve, the means being shown in position with the lower spring applying forces opposing opening of the valve.

While my invention is adapted to and intended for application to internal combustion motors generally, it is primarily applicable to the operating conditions met with in the motors of automotive vehicles, such as the motor Vehicle or automobile. stance as an example for purposes of describing and explaining the principles and features of the invention, selected an adaptation thereof designed for use with a typical motor of a motor vehicle. As such motors are more or less standard or conventional and well understood by those familiar with the art, I have in the accompanying drawings deemed it only necessary to illustrate those parts of a typical motor with which apparatus embodying the invention is associated or cooperates in use and operation.

As representative of a typical and well known motor vehicle internal combustion motor, I have shown in Fig. l of the drawings, the intake manifold M of the motor connected by the intake line L with the carbureter C, through which the fuel mixture is drawn from the carbureter into the usual combustion chambers of the motor cylinders by the suction action of the motor pistons, all in the usual and well-known manner.

I have therefore in the present in- The usual motor throttle or butterfly valve V is shown mounted in the intake line L for rotation to open and close such line to control. the flow of fuel to the motor and thereby control the operation of the motor. The valve V is actuated and controlled by the driver of the vehicle, through a valve operating mechanism that includes the rotary shaft4 i coupled to the throttle valve V, and the link 2 pivotally connected between and operatively coupling an arm 3 on shaft I and an end of the rock arm 4. The arm 4 is suitably coupled with and actuated by the usual driver controlled accelerator or the like control memberA (not shown).

The motor throttle valve V and its driver actuated operating mechanism i-2-34, are shown in Fig. l of the drawings, with the throttle valve in its normal so-called closed position or setting for idling operation of the motor. The throttle valve V is rotated to open positions by upward Swinging of arm 4, which through link 2, rocks arm 3 and rotates the valve to opened positions for increased flow of fuel mixture from carbureter C to the intake manifold M and the motor to accelerate or increase the speed and power of the boat.

With the throttle valve V in its -motor idling or closed setting of Fig. l, it was found that the particular motor of the example hereof developed a vacuum of the order of approximately 2O inches on a vacuum gauge, in the intake line L, manifold M and the motor, against which the idling motor must operate. Such a vacuum condition with the vehicle at rest andthe motor idling is not, however, a serious condition or one that contributes largely to substantial fuel waste and power loss, particularly when it is considered that a motor and its fuel mixture supply must be adjusted for an efficient idling operation of the motor, and that to obtain such eicient idling operation, a relatively rich fuel mixture must be steadily supplied to the motor in ample quantity by a positive suction force.

From the idling operation of the motor, if the vehicle is placed through the usual shift of gears into high. gear with the throttle valve V opened to cause the motor to drive the vehicle at a speed of approximately 10 miles per hour. then with the particular motor and vehicle of the present example, a Vacuum in the intake of the order of approximately 20 inches was found to exist. If then the motor throttle V is. further opened to increase the speed of the motor and the vehicle, the vacuum in the intake drops or decreases rapidly with the opening of the throttle valve, and if the throttle valve of the motor is opened to maximum open position or full throttle the vacuum in the intake. drops to a very low degree corresponding to an order of approximately l or inches on a vacuum gauge. However, as the motor and vehicle accelerates by the opening of the throttle the driver naturally slowly closes the throttle with the result that the vacuum ,in the intake line and manifold of the motor builds up or increases again very rapidly and this increasing vacuum will attain the very high degree of the order of 25 to 26 inches. A vehicle motor operates under such high intake vacuum conditions for the majority of the time when the 'vehicle is being driven in the range from approximately 20 to 60 miles per hour or higher, and the major fuel waste and motor power loss with the other disadvantages hereinbefore referred to, due to the high vacuum conditions in the motor intake are encountered in this range of operation.

In accordance with the principles of my invention If provide for an automatic control of the intake vacuum conditions to reduce the high Vacuum, and accompany such reduction with dilution of the fuel mixture, in the motor intake during and throughout the ranges of motor vehicle driving speeds at which such high vacuum is mainly encountered. I accomplish this vacuum control through the medium of an air admission valve in the motor intake line Lv intermediate the carbureter C and themotor intake manifold M to the motor, which valve is controlled automatically by forces applied thereto as the differential between the force of the intake vacuum tending to open the valve, and predetermined varying forces independently applied to the Valve to close it, the application of such independently applied forces being synchronized with and according to the setting or position of the motor throttle Valvel V. Such an intake air admission valve may as in the example hereof be embodied in a valve unit I0 which is coupled into communication with the intake line L by the conduit vor air pipe il, as shown in Fig. 1 of the drawings, for discharging air into the intake line to break down a vacuum condition therein and at the same time dilute or reduce the richness of the fuel mixture drawn up through the line from the carbureter C. f

The valve unit I9 in the design and construction thereof here illustrated includes, referring now particularly to Figs. l, 2, 3 and 4 of the drawings', a main casing or housing I2, preferably although not necessarily of generally cylindrioal form, having an open internally threaded lower end i 4 and a decreased diameter upper end portion i5 terminating in the head l5 providing a vertical boss having an internally threaded axial bore 56a therethrough. The casing or housing i2 is formed with a horizontal laterally extended air discharge outlet Il from one side thereof having a relatively large internal diameter and internally threaded at its outer end for coupling to the air conduit orpipe Il to place the interior of casing l2 into communication with the motor intake line L.

The lower end of the casing l2 of the valve unit l0 receives a valve seat forming an air in- 4* take member i8 that is threaded into the casing and pro-vides a depending vertically disposed and open end air intake tube portion I9 with the bore of tube ii! continued axially through member I8 and ope-ning at its upper end into the chamber therearound. This ring 2 I l is formed with spaced vertically disposed external ribs Zla spaced therearound (see Fig. 4 in particular), and a radially disposed set screw or the like 2lb is threaded through the side wall of casing i2 opposite the casing air discharge il to engage at its inner-end between a pair of the spaced ribs Zia and maintain the ring 2! in adjusted position.

Within the air chamber formed by the valve unit casing l2, for cooperation with the valve seat 2U to open and close the air inlet tube to the chamber, the vertically movable or reciprocal air admission valve 22 ismounted for automatic operation in accordance with the principles of the invention. The air valve 22 in the particular example hereof, is mounted in horizontal position on the upper side of the member I8 over the upper inlet end of the air passage through member I8, and is provided with the annular beveled valveface 23 therearound for engaging andV seating on valve seat 20 with the valve in lowered, closed position (see Fig. 2). The valve has a diameter greater than the maximum diameter of valve seat 20 and provides an annular ilange' 24 therearound which extends over the adjusting ring 2l but is spaceda distance above the upper surface of member I8, even with the valve in lowered and sealed position of Fig. 2. The valve 22 is also provided with a depending axial body portion 22a that includes the spaced vertical ribs 22h extending radially therefrom in diametrical- 1y opposite pairs (see Fig. 4) which body and ribs extend down into the cylindrical bore forming the air inlet passage through member I8, with the ribs 22o in Vsliding engagement with the passage walls to form a guiding and centering structure for Athe valve in its vertical reciprocation between opened and closed positions. Y

The air admission valve22 of the valve unit Ill is normally forced downwardly and maintained in Seated closed position of Fig. 2, by an upper force exerting member, such as the expansion coil spring 25. In the embodiment of the valve unit here shown, the valve 22 is formed with an axial bore 22C extending thereinto from the upper side f of the valve, and a rod 26, forming in eiect a stem for the valve, is fitted into bore 22e and supported therein by a flange 26a on the rod which engages and rests upon the upper face or surface of the valve, as will be clear by reference to Fig. 2 of the drawings. The rod 26 extends upwardly through the casing and is slidably received at its upper end into an adjusting tube 2l that is externally threaded and screwed down through the internally threaded bore IEa of the end boss I6 of the casing portion I5. 'Ihe` upper end Of adjusting tube 21 is formed with the head 21d, and a set or lock nut 2lb is provided on the tube between the head and the upper end face of boss I8, for securing the tube in an adjusted position referring now to Fig. 2 of the drawings. A'cover or cap 28 is removably threaded onto the externally threaded boss I3 of casing I2 and encloses and covers the upper end of the adjusting sleeve 2l'.

The valve spring 25 is mounted around rod 26 within the casing chamber and is held between vertically spaced plate members or washers mounted on the rod. The lower of these washers 22 rests upon a spacer 29a which is supported in position on the rod by an enlargement 26h of the rod above the rod flange 26a.. The upper spring holding washer Sil is slidably mounted on the rod and is held against upward movement thereon by the lower end of spring force adjusting tube 2l. Thus, the spring 25 is held between the lower washer 22 and upper washer 33, preferably under initial compression, so that the expansive force of the spring, until overcome by an upwardly acting force on the valve, holds the valve in closed position on its seat 20. The valve 22 and rod 26 are free Vto move upwardly to unseat the valve to open position by compressing spring 25 between washers 2S and 3i?. The initial compression and force exerted by the spring can be adjusted by screwing tube 21 downwardly to increase spring force and upwardly to decrease the force exerted on the valve by the spring.

Following the principle of a further important feature of my invention, I make provision for the application of valve closing forces to the valve 22 in addition to the force normally constantly applied by the valve spring 25, but such additional closing force is only applied under certain motor throttle valve setting or positions. For instance in carrying out such feature in the embodiment of Figs. 1 to 4 of thedrawings, a coiled contractile spring 3| is connected or coupled at one end to a depending axial ear or lug at the lower or under side of the valve guide body 22a, and extends downwardly therefrom to and is connected with, means operated by or under control f the motor throttle operating mechanism for expanding the spring to place it under tension applying downwardly acting closing forces to valve 22, or for releasing the spring to remove such forces from the valve. In the present instance the spring 3| is controlled by the action of the vacuum in the motor intake line and the functioning of the vacuum for this purpose is in turn controlled by the throttle valve actuating mechanism in accordance with the position or setting given the motor throttle valve.

For this purpose, in the form of the invention of Figs. 1 to 4, a cylinder 32 is mounted and supported positioned below but axially alined with the air admissionvalve 22, by a bracket structure 33 secured to the depending air inlet tube I9 of the air valve unit I0. A piston 34 is reciprocally mounted in and has a sealing t with cylinder, and this piston is provided with a piston rod 35 extending upwardly therefrom and outwardly through the upper end or head 34a of cylinder 32. The upper end of piston rod 35 has a head 35a at the exterior of the cylinder to provide a stop limiting downward movement of the piston in the cylinder and giving the maximum lowered piston position as spaced a distance above the lower cylinder head, as shown in Fig. 2 of the drawings. An extension pin 36 is threaded adjustably into an axial bore in the upper end of piston rod 35, and a lock nut 36a is provided thereon for securing this pin in any desired vertically adjusted position. The lower end of the contractile spring 3l depending from air valve 22, is connected to the upper end of piston rod pin 36, and the relative adjustment between the spring, pin and piston is such that with the piston in maximum lowered position, spring 3l is held under tension between the piston and valve 22 to apply valve closing force to the valve, while with the piston raised, or lowering force removed therefrom, the spring force on the valve is released. In order to connect the lower end of cylinder 32 with the source from which piston 34 is operated, the lower wall or head of the cylinder is provided with an internally threaded bore or port 36a. therethrough (see Fig. 2).

The valve unit I and the valve controlling cylinder 32, are mounted as a unit on a motor, referring now to Fig. l of the drawings, with the air conduit Il coupled between and connecting the air discharge or outlet I I of the unit with the motor intake line L at a point therein intermediate carbureter C and the motor intake manifold M. The port 34a of the cylinder 32 is connected and placed in communication with the intake line L of the motor at a point therein adjacent the connection of conduit II, by a tube 31, so that with this tube open, the piston 34 in cylinder 32 is subjected to the prevailing Vacuum condi- CFI tion in the intake line. As the actuation'or control ofv piston 34 by the intake vacuum is determinedby and subject to the setting or position of the motor throttle valve V in accordance with this feature of the invention, a valve 38 is provided in tube 31 for opening and closing the tube and this valve is operated by the throttle valve actuating mechanism. The valve 38 may be of any suitable type but in the example hereof is of the conventional rotary barrel or plug type.

The tube 31 is provided with an air vent 31a therein intermediate valve 38 and cylinder 32 for relieving vacuum to permit free upward movement of the piston in cylinder 32, when valve 38 closes.

The valve 38 in tube 31 is located at a 'point convenient for operative connection with the throttle Valve actuating mechanism, and in this instance is provided with a horizontally disposed and vertically swingable operating arm or lever 3.9 for rotating the valve to opened and closed positions. The free end of arm 39 is pivotally connected to the lower end of a link 4B which extends upwardly to and is pivotally coupled to the arm or lever 4 of the motor throttle valve actuating mechanism. The link 48 is ofthe adjustable length type to enable relative adjustment between the positions of the arms 4 and 39, which it operatively connects. The valve 38 and arm 39 with link 4U are so set and relatively adjusted that when the throttle valve V is in closed or vmotor idling position as shown in Fig. .2, due to the position of arm 4, then the valve 38 in tube 31 is open to place the lower end of cylinder 32 below piston 34 in open communication with the motor intake line L. The arrangement of link 40 and valve operating Aarm 39 is such ,that as arm 4 is rocked to open throttle valve V, the valve 38 is rotated to close tube 31, but does not reach closing position until the throttle valve has .opened from idling position to a predetermined position for an approximate motor speed, say, a motor speed corresponding to a vehicle speed .in high gear and on a level road, of the order of approximately 20 miles per hour.

Now, in operation of the motor with the valve V in idling setting and the vehicle at rest, the

valve 38 in tube 31 is open. As with the motor of the example there is found to be an intake vacuum of the order of lapproximately 18 to 20 inches, this vacuum condition creates a suction through tube 31 and in cylinder 32 beneath piston 3i, with the result that the piston is sucked or diawn downwardly to the position shown :in Figs. l and 2 and the contractile lower spring 3| for the air valve 22 is placed and held under tension exerting a downward acting force on the valve 22 opposing its opening. The upper spring is constantly applying downwardly acting forces holding valve 22 closed, so that in the motor idling condition it is the combined force of the upper and lower springs 25 and 3! that acts to hold valve 22 in its closed position against opening. The vacuum condition of say 18 to 20 inches with the motor .idling also acts through the conduit l1 to create a suction force tending to draw or .lift valve 2-2 to open position, but the combined forces of springs 25 and 3| are of a magnitude to hold the valve 22 seated and vclosed against the suction action of the intake vacuum. Thus, for idling condition, 'the intake vacuum is maintained to insure positive supply of `the required combustible mixture to the .motor 'from carbureter C for smooth and efficient idling operation of the moton As the throttle valve V of the motor is opened and until the motor speed reaches a speed for the instant example of the approximate order of 600 R. P. M., the idling conditions prevail and the air admission valve 22 is maintained closed by the .combined forces of the upper and lower springs 25 and 3| and the valve will be held closed until a vacuum condition of greater than 18 to 2) inches is established in the motor intake line L. After the throttle valve V reaches the open position for the aforesaid speed, then arm 39 is rocked by .link 40 to rotate valve 38 to position closing tube y3i! and shutting `off cylinder 32 from intake line L, so that, the vacuum or suction condition in cylinder 32 is relieved through vent 3io, and .the downward acting force on piston 34 `and spring 3| removed and theA tension-in spring 34 is relieved. This releases the spring 3i, which then is inactiveon valve 22, and the airvalve is only held in seated and closed position by the force exerted thereon by the upper;

spring A2,5.

The force exerted by the upper spring 25 is of a magnitude to .maintain valve 22 closed against. the suction force acting thereon to open the valve, established by a motor intake vacuum of the order of '1 :to 10 inches. Hence,

with the motor throttle valve V.in opened positions vand the lower spring 3l inactive, the air valve 22 is automatically opened when the intake vacuum exceeds '1 to 1-0 inches, and air is admittedfrom the inlet tube II9 past valve 22 and through conduit i1 into the intake line L. This admitted oi course breaks down Athe vacuum and also dilutes the fuel mixture being drawn from the carburetor C, whereupon with the decrease in'vacuumsspri-ng 25 forces valve 22 back to closed'pcsition ,shutting oi further air admission. As -a vmotor vehicle operating in the range from around 20 M. P. H. up develops an intake vacuum of the order above '7 to 10 inches, with the air valve :arrangement of the invention the intake vacuum through this range is maintained at or below the order of 7 to 10 inches automatically by the opening of valve 22 against the force of upper spring 25 whenever the vacuum tends to increase above the indicated allowable limits. Thus, by the operation of the Vmotor under .such reduced intake vacuum conditions the powerris increased with a reduction in motor wear, while a :substantial reduction in fuel consumption is attained together with more perfect combustion and reduction in carbon conditions in the motor and exhaust lines.

With the motor operating in the range at which the air valve 22 is controlled bythe force of the upper :spring 215 alone, of course upon rapid acceleration by wide opening of the throttle valve V., the intake'vacuum reduces rapidly and the valve 22 remains closed, but as the desired speed is attained the throttle valve is slowly closed and intake vacuum builds up rapidly until the allowable limit -determined by 4the v'force of spring 25 is reached, whereupon valve 22 is opened and air is admitted to the intake t'o vbreak down the vacuum .and maintain it at the 'predetermined limit. The air so admitted to the intake lin-e dilutes fthe fuel mixture 'to effect-saving "for fuel and to reduce overcharging and jfouling the motor. `When the throttle Vis closedV to idlin'g'pos'ition lwith the vehicle then coasting, as by deceleration from higher speed, or infcoasting down grade with the motor idling, immediately the throttle operating mechanism reachesa Yposition for the predetermined setting at which valve 38 is opened, the intake vacuum drawsvpiston 34 down and the force of lowerspring 3| is applied to the air valve 22, so that the allowable intake vacuum is increased, in the specic example hereof to the order of 18 to 2O inches. With the vehicle coasting and the motor idling, the motor is of course functioning as a pump and a very high vacuum will be established in the intake line, but the combined force of the upper and lower springs 25 and 3| will not permit the vacuum to exceed the predetermined limit, say, the 18 to 20 inches of this example, because as such limit is reached valve 22 is opened to admit air and reduce the vacuum, while at the same time reducing the richness of the fuel mixture drawn into and charging the idling motor. By maintaining the increased limit of allowable vacuum.

with the motor idling and inthe low speed range, the desired richness of mixture is preserved as well as an ample degree of vacuum for vehicle braking effect, while the effects of the normally very high intake vacuum under such operating conditions are eliminated. f

The force applied by the upper spring 25 is adjustable by means of the adjusting sleeve 21 to increase or decrease the normal initial compression of this spring. Similarly, the force exerted by lower spring 3| is adjustable by raising or lowering the pin 36 in the piston rod 35. Under certain conditions when found expedient, the adjusting ring 2| can be set in a raised position to obtain a slower action of the valve 22 or to prevent chattering of the valve on its seat 22. In such raised position the ring 2| forms the seat for closing engagement by the valve ilange 24.

Of course, the diameter and volumetric capacity of the air intake tube I9, the port for valve 22 and the conduit I l to the intake Vline L must be such as to permit passage of suflicient volume of air to the intake when the air valve is opened. -For example, with the embodiment of the invention here shown designed for a particular motor having a cylinder bore of Ssg inches and an intake manifold of inside diameter of 1% inches,I employ an inside diameter forthe air conduit of 11A inches, with an air valve for a valve seat of 1%, inches. The suction tube from the intake line L to the cylinder 32 is of ,is inch diameter to 1/4 inch diameter, depending upon the length of the tube. These dimensions are indicative only and not given as exact limitations, but serve to point out the relative dimensions as determined from the illustrated example of an actually operated and used device of the invention.

A modified form of controlling means for the lower air valve spring 3| is sho-wnin Fig. 5 of the drawings and embodies the substitution of a solenoid S for the intake suction or vacuum operated piston 34 of Figs. 1 to 4. A supporting bracket 33 is secured to and depends from air inlet tube I9 of the air valve unit l0, and a casing or housing H is secured to and depends from this bracket with the solenoid S enclosed therewithin. 'Ihe armature 4| of solenoid S is vertically axially alined with tube I9 and has an upwardly Vextended axially disposed rod 42 threaded into the armature, slidably extended through casing H, and bracket 33', and provided with a stop forming head 42a for engaging the upper side of the bracket to limit downward movemnt of the armature and rod. A pin 43 is screw threaded axially into rod 42 and is coupled at its upper end to the lower end of springl, the pin being proc vided with a lock nut 43a for securing the piny Y in a vertically adjusted position in rod 42.

The oppositey terminals of thel solenoid-44 and 45, are connected by wires 44a, and 45a, with one terminal 45 of an electric switch D and with one terminal of a battery B or other source of current. The opposite terminal of battery B is connected by wire 4l to the opposite terminal 43 of the switch, which terminal is suitably grounded. The switch D is of the knife type and includes the blade 49 pivotally mounted on switch terminal` 48 for vertical swinging to. and from circuit closingengagement with switch .terminal 46. -The free end of switch blade 49 isl pivotally coupled to the lower end of link 40 (see Fig. 1) which link is operatively coupled to av suitable 'operating member of the throttle valve actuating mechanism, such as member or arm 4 of Fig. 1. When installed, switch D issuitablymounted in a convenient position on the motor or vehicle for operative coupling with the motor throttle valve actuating mechanism.

"The solenoid formrof the invention of Fig. 5 in operation, has the switch closed with the motor throttle valve in idling position, so that the solenoid S is energized to hold armature 4| in lowered position and place the spring 3| under tension toA apply its force to the air valve of unit Ill, as explained in connection with Fig. 1. As the motor throttle valve is opened, link 40 swings switch blade 49 from contact with terminal 46, and at a predetermined throttle opened position the switch breaks the circuit to solenoid S and deenergizes the. solenoid so that armature 4| is released and the force of spring 3| on the air valve or" unit Il] is removed. The operation and functioning of the air valve `22 is of course the same as that described ior Figs. 1 to 4.

Another form of switch for controlling the solenoid circuit is more or less diagrammatically shown in Fig. 6 of the drawings, and includes an insulating material base 50 having a. contact 5| yieldingly mounted on the base by a spring 52.'

An opposite contact 53 is mounted in iixed position on a movable arm 54 which is operatively coupled to the motor throttle'valve actuatingl mechanism so as to be moved to engage contacts 5| and 53, to close the circuit to solenoid S when the motor throttle Valve is in idling position, and to disengage and break the circuit at a predetermined open position of the throttle valve. Preferably in idling position of the motor throttle valve, the contacts are engaged to force contact 5| inwardly toward base 5D against spring 52. Thus, Contact 5| is forced to follow and remain in engagement with contact 53 as the latter moves therefrom for a period before contact is broken, this period of engagement determining the open position of the throttle valve at which the solenoid circuit is broken and the force of lower spring 3| released from the air valve of valve unit I0. By adjusting contact 53 on arm 54, the period of contact engagement prior to and in advance of idling position of the valve may be determined.

In Fig. '7 of the drawings, 1 have illustrated another form of lower valve spring controlling means, which is of the solely positively and directly operated mechanical type. vAccording to the illustrated example of such mechanical form, the depending bracket 33 on the air tube I9 of the valve unit IU, is provided with a sleeve 55 mounted in lvertical position extending through the lower cross member or brace of the bracket and in axial alinement with tube I9. A cross arm 55 is secured to and extends from opposite sides of sleeve 55 beneath bracket 33 and is provided at its opposite ends with the depending arms51 and 58. A lever 59 is pivotally connected to the lower end of arm 58 and extends generally horizontally therefrom through a vertically slotted portion 51a of the opposite arm 51. Lever 59 extends a distance beyond arm 51 and is pivotally connected at its free end to the operating link i0 (Fig. 1) by which it is connected with the motor throttle valve actuating mechanism, for raising as such mechanism opens the valve and lowering as it closes the throttle valve.

The lower spring 3i' for the air valve 22 is of extended length and passes downwardly into sleeve 55. The lower end of spring 3| is connected by a cable to a shackle 6| pivotally con- Y nected to lever 59 between `depending arms 51 and 58. The lever 5S in its lowered position has a downward inclination from arm 58, and is provided with a series of spaced holes 51a for mounting shackle 6| on the lever in adjusted positions to vary the amount of travel of spring'l in lowered position of the lever 59 in relation to the throttle valve opening.

With the form of Fig. 7 installed on a motor and in operation, when the motor throttle valve is in idling position, the link li from the valve actuating mechanism holds lever 5S in the downwardly swung position as shown in Fig. '7, with the cable 66 placing lower spring 3l under tension to apply valve closing force to the air valve 22, in addition to the closing force applied by upper spring 25. As the motor throttle valve is opened, link iii raises lever 55, until at a predetermined open position of the throttle valve, the tension applied to spring 3l by cable 6D is released and the closing force applied by spring 3i to valve 22 are removed, with the air valve 22 then held closed solely by the force applied thereto by the upper spring 25.

Thus, in accordance with the basic principles and several features of the invention as exemplified by the several embodiments illustrated and described herein, an internal combustion motor is operated under reduced intake vacuum throughout the major portion of its speed range above a predetermined low speed to thereby reduce fuel consumption and increase power and eiiiciency, while in the range from the predetermined low speed to and including motor idling, the maximum allowable intake vacuum is increased over that for the higher speed range to approximately normal but is not permitted vtoincrease above such maximum under any operating conditions encountered. In this manner and by this method of controlling motor intake vacuum and fuel mixture richness, the increased performance, economy of operation and other advantages hereinbefore referred to, are obtained.

It will be evident that various changes, modiiications, variations, substitutions, eliminations, and additions might be resorted to without departing from the spirit andscope of my invention, and hence, I do not wish to limit myself in all respects to the exact 'and specic disclosures of the examples of the invention hereof.

What I claim ist- 1. The combination with the intake line of an vinternal combustion motor, including a throttle valve in said line and actuating mechanism for the valve, of a normally closed air valve for opening to admit air into the intake line to prevent increase of vacuum therein, means applying a force to said air valve to maintain the valve closed against'the 'valve opening force ofv a pr-e-y determined mam'mum Vacuum in theA intakeline, said valve opening against the force of said means by an increase in the intake vacuum above' said maximum, and a normally inactive means for applying additional closing force to said air valve, said normally inactive means rendered active to increase the closing force on the valve when the motor throttle valve is in a predetermined motor operating position.

2. The combination with the intake line of an internal combustion'motor including a throttle valve in said line and actuating mechanism for. the valve, of a normally closed air valve for opening to admit air into the intake line to prevent increase of vacuum, means applying forces to said air valve to maintain the valve closed against the valve opening force'of a predeter mined maximum vacuum in the intake line, said valve opening against the force of said means by.y

an increase of the intake vacuum above said maximum, and means controlledby the throttle valve actuating mechanism for reducing the closing force applied to the air valve by said force applying means only after the throttle valve is partially opened to thereby reduce the maximum intake vacuum at which Said air valve is opened.

3. The combination with the intake line of an internal combustion motor, including Va motor throttle valve and its actuating mechanism, of a normally closed air valve for admitting air into the intake line to prevent increase in the vacuum in said line, said air valve opened by the suction force of a vacuum in the intake line, means applying closing forces to said air valve of a magnitude to prevent opening thereof until the intake vacuum reaches a predetermined maximum, means operatively coupling the throttle valve actuating mechanism with said valve closing force applying means for causing said means Vto reduce the closing forces applied to the valve only throughout the operating range of throttle vvalve positions above a predetermined open position of the throttle valve.

4. The combination with the intake line of an internal combustion motor, including a motor throttle valve and its actuating mechanism, of an air valve for admitting air into said intake line to prevent increase in the vacuum in the line, said valve opened bythe suction effect of the intake vacuum, a sp-ring normally maintaining said valve closed against a predetermined maximum vacuum, a second spring for applying closing forces to said valve to augment the force applied by said rst spring and to increase' the maximum vacuum in the intake line for opening said valve, means for operatively associating and disassociating said second spring with and from force applying relation with the air valve, and said means controlled by the throttle valve actuating mechanism to cause said second spring to apply closing force to the air valve with the throttle valve in a predetermined range of positions and to disassociate said spring from the air valve during the remainder of the range of positions of the throttle valve. y

5. The combination with the intakeline of an internal combustion motor, including a motor throttle valve and its actuating mechanism, of an air valve for admitting air into said intake line to prevent increase in the vacuum in theA vacuum, a second spring for applying closing f forces to said Valve in addition to the closing force of said first valve to thereby increase the maximum intake vacuum at which the air Valve opens, means actuated and controlled by the suction effect of the intake vacuum for operatively associating and disassociating said second spring with and from force applying relation with the air valve, a valve for opening said means to and shutting the same from the suction of the intake manifold, and said latter valve operated by the motor throttle valve actuating mechanism in accordancefwith the position of the throttle valve.

6. The combination with the intake line of an internal combustion motor, including the motor throttle valve and its actuating mechanism, of an air valve for admitting air into the intake line to prevent increase of vacuum in such line, said valve adapted to be opened by the suction effect of the intake line vacuum, a spring normally maintaining said air valve closed against a predetermined maximum intake vacuum, a second spring for applying closing force to said valve in addition to the force of said iirst spring to thereby increase the maximum intake Vacuum for opening said valve, a suction operated means coupled with said second spring and in communication with the intake line, a valve controlling communication of said means with the intake line for opening to cause operation of the means to apply the force of the spring to the air valve and for closing to cause said means to release application of closing force to the air valve, and said valve controlling communication between the intake line and said suction operated means opened and closed by the throttle valve actuating mechanism in accordance with the position of the throttle Valve.

7. The combination with the intake line of an internal combustion motor including the motor throttle valve and its actuating mechanism, of an air valve for admitting air into the intake line to prevent increase of vacuum in such line, said valve adapted to be opened by the suction eiect of the intake line vacuum, a spring normally maintaining said air Valve closed against a predetermined maximum intake vacuum, a second spring for applying closing force to said valve in addition to the force applied by said first spring to thereby increase the maximum intake vacuum for opening the valve, a solenoid including an armature connected with said second spring, an electrical circuit for supplying current to said solenoid, a switch in said circuit for opening and closing the same, the armature of said solenoid, when the latter is energized, maintaining said second spring in position applying closing force to said valve, and releasing the spring when the solenoid is de-energized, and said switch operatively connected with the throttle valve actuating mechanism whereby the switch is opened and closed in accordance with the position of the motor throttle valve.

8. The combination with an intake line of an internal combustion motor, including a throttle valve in said line and actuating mechanism for the throttle valve, of a normally closed air valve for opening to admit air into the intake line to prevent increase of vacuum therein above a predetermined maximum vacuum, means applying forces to said air valve to maintain the valve closed against the valve opening suction eiect of a predetermined maximum vacuum inthe intake line, means operated by the suction effect of the vacuum in the intake line for increasing the closing force applied to theV air valve by said force applying means, and said suction operated means operated by the throttle valve actuating mechanism to apply and remove the increased closing force on the air valve in accordance with the position of the motor throttle valve.

9. In apparatus for automatically controlling the vacuum in the intake line of an internal combustion motor, an air admission valve unit for connection with a motor intake line for admitting air thereinto, said unit including a vertically reciprocal air valve for raising to open air admitting position, by the suction effect of the vacuum in an intake line and for lowering to closed position shutting off' admission of air to the intake line, an expansion spring above said Y valve continuously exerting downwardly acting force thereonto close the valve, a con-,

tractile spring beneath the valve and coupled thereto for applying downwardly acting force to close the valve in addition to the forces applied by said upper spring, mechanism coupled to the lower end of said contractile spring for placing the same under tension to apply closing force to the valve and for releasing the tension thereof to remove such forces from the valve, and said mechanism adapted to be operatively coupled with the throttle valve actuating mechanism of a motor for applying and removing'said lower spring forces to and from the valve in accordance with the position of the motor throttle.

10. In apparatus for controlling the vacuum in the intake line of an internal combustion motor, an air admission Valve unit for connection with a motor intake line for admitting air to such line to reduce the vacuum therein, said valve unit including a horizontally disposed valve seat and a vertically reciprocal valve for cooperation with said seat for opening and closing said unit, an expansion spring in the unit above said Valve and continuously applying closing forces thereto, said valve adapted to be opened against said spring by the suction effect of a predetermined vacuum in the motor intake line, a contractile spring below said valve and connected thereto for applying additional valve closing forces to the valve to thereby increase the maximum intake vacuum capable of opening said valve against the combined forces of the upper and lower springs, means coupled with said lower spring for placing the same under tension between the valve in closed position and such means and for releasing the tension on said spring and removing the closing force thereof applied to said valve, and said lower spring controlling means adapted to be operatively associated with the motor throttle Valve for applying and releasing the additional valve closing force of said lower spring from and to the valve in accordance with the position of the motor throttle valve.

11. The combination with an intake line of an internal combustion motor, including a throttle valve and actuating mechanism therefor, ci a normally closed air valve for opening to admit air into the intake line to prevent increase of vacuum therein above a predetermined maximum vacuum, means applying forces to said air valve to maintain the valve closed againstl the valve opening suction effect of a predetermined maximum vacuum in the intake line, electrically controlled means operatively associated with said force applying means for actuation to increase the valve closing force applied by such latter means, an electrical circuit for supplying current to said electrically controlled'means, a switch in said circuit for opening and closing the same, said electrically controlled means when energized by said circuit actuated to increase the valve closing force applied by said force applying means, and said switch connected with the throttle valve actuating mechanism whereby the switch is operated to open and close said circuit in accordance with the position of the motor throttle valve` 12. The combination with the intake line of an internal combustion motor, including a motor throttle valve and actuating mechanism therefor, of anormally closed valve for opening to admit air into the intake line to prevent increase of vacuum in the line, means'applying a force to said air valve of a magnitude sufficient to maintain the valve closed against a predetermined xed maximum intake line vacuum, said valve opening against said force applying means under the action of an increase in the vacuum above said iixed maximum and means associated with the throttle valve actuating mechanism for increasing the magnitude of the closing force applied to the air valve by a substantially fixed amount throughout .the portion of the operating range of the throttle valve from closed position to a predetermined open position.

13. The combination with the intake line of an internal combustion motor, including a throttle Valve and actuating mechanism therefor, of means for admitting air into the intake line when the vacuum in such line exceeds a predetermined substantially constant maximum, and means controlled by the throttle valve actuating mechanism for adjusting said air admission means to increase the said vacuum to a substantially constant greater maximum at which air is admitted only when the throttle valve is in that portion of its operating range between normal closed position and a predetermined open position.

14. The combination with the intake line of an internal combustion motor, including a motor throttle mechanism for controlling the operation of the motor, of means for admitting air into the intake line only when the Vacuum in such line exceeds a predetermined substantially xed and constant maximum, and means controlled by the motor throttle mechanism for causing said air admission means to admit air at an increased substantially fixed maximum vacuum :for that portion only of the full operating range of the motor between motor idling position and a pre-- determined open position of the throttle mechanism.

15. The method of regulating the intake Vacuum of an internal combustion motor, which consists in; admitting air to the motor intake to lower the vacuum therein whenever said vacuum tends to exceed a predetermined and fixed magnitude during the motor operating range from and including idling position of the motor throttle to a predetermined opened position thereof; and admitting air to the motor intake whenever, during the operating range of the motor between the aforesaid opened position of the throttle and maximum open position thereof, the vacuum tends to exceed a lower predetermined and xed magnitude.

16. The combination with the intake line of an internal combustion motor, including a motor throttle valve and its actuating mechanism, of a normally closed air valve for admitting air into the intake line to prevent increase in the vacuum in the motor, said air valve being opened by the suction force of a vacuum in the intake line, means applying closing forces to said air valve of a magnitude to prevent opening thereof until the Vacuum attains a predetermined and substantially fixed and constant maximum, and means operatively associated with said valve closing force applying means-for causing said means to reduce the closing forces applied to the valve to another predetermined xed maximum only throughout the operating range of throttle Valve positions above a predetermined open position of the throttle valve.

17. The combination with an internal combustion motor, including a motor throttle valve and its actuating mechanism, and an intake line for the motor, of a normally closed air valve for admitting air into the intake line to prevent increase in the motor vacuum, said air Valve being opened by the suction forceof a vacuum in the motor, means applying closing forces to said air valve of a magnitude sufficient to prevent opening of the valve until the vacuum attains a predetermined substantially fixed and constant maximum, and means operatively associated with said valve closing force applying means for causing said means to reduce the closing forces applied to the valve to a lower substantially constant magnitude only throughout the operating range of throttle valve positions between a predetermined open position of the throttle valve and maximum open position thereof.

THOMAS CLARENCE MARSHALL. 

